Difference between bump map and normal map
This has nothing to do with blender, but could be useful anyway.

The normal map contains pixels with vectors. Each pixel has a vector, where is that pixel pointing. In the standard light blue purple color, it is pointing straight out from the surface. As the color changes, it points in different directions.

A heigh map (or bump map) has a height value stored as a value between black (lowest) and white (highest).

The bump maps in your post doesn't look like it will produce roof tiles when projected on a flat surface.

They describe about the same information, in different ways. 

Looking at a single pixel in a normal map, it is impossible to say what height it is. Just the way the surface is tilted (direction and amount). But if you look at more pixels surrounding it, you can build up a relative height. If you stand on a slope, you can see that, up the slope, the ground is higher.

Looking at a single pixel in a height map, it is impossible to say what slope it is. But you know exactly how high you are. But by looking at your neighbours, you can work out a slope.

To work with a normal map in a material in blender, you have to run it through a Normal map node. This also have a strength value, to determine the scale of the bumps.

EDIT:
To me it looks like your bump map isn't meant to be put on a flat plane. It looks like baked normals for a lowpoly model of roof tiles. I don't know where you got these maps.

The normal map you have, that will give roof tiles when mapped onto a flat plane. Not very good ones if you get close. But from a distance, it will work.

Here is an image I made, showing the difference. Normal map on the left.